I am looking into replacing my Sovteck 6922 (3 of them) on my Kora Eclipse pream (www.kora.net). I was told that I will get "better" results if I used other tubes. I am new to the tube world (I am an end-user only). Can anyone suggest cost effective alternatives? I know that one gets what one pays for but I am not in the position to buy $250+ each for Amperex NOS. I notice that Tesla is quite affordable.

Unless you find them yourself in an abandoned warehouse, don't believe any claims that tubes are NOS.
The Sovtek tubes are good, reliable, and available. There may be other brands out there that sound better--you'll *always* be able to find someone that champions some brand of tube or another, just as there are people who would perish rather than use Motorola, IRF, or whatever--but I've not heard any consistent reports that favor one brand of 6922 over another.
Don't get sucked into putting in a 6NP1 (I think I've got that right) unless you intend to diddle the bias a bit. They are *not* equivalent to the 6922. If you do make the change, take notes on the circuit as it is now--you may want to go back to 6922/6DJ8s later.

You're right.I think you meant 6N1P though which is not an equivalent of the 6N23P-EB/6922 which I find excellent technically.

Techno,

The manufacturer probably designed your preamp with the Sovtek
6922's so I'd stick with that.Other manufacturers tubes would sure sound different,not necessarilly better.
BTW anyone ever liked the TESLA ECC88-E88CC ?
As much as liked their TFK ECC803S style E83CC's I never was pleased with their E88CC.
If the implementation is critical (noise,gain etc.) I'd ask around for a tightly selected set and buy some spares if satisfied.

A cautionary tale:
I once had the Musical Fidelity X10D and was looking for an upgrade for the hard working 6922 valves. I chose some Mullard ECC88 (European equivalents) and duly plugged them in. The result was horribly sweet and syrupy and not at all to my taste. The moral is that equipment manufacturers tune their circuits to get the best from a particular readily available valve brand and trying a fancy (and expensive) NOS valve might just ruin the overall presentation.
I am with Frank - stick with the Sovteks and save yourself a packet on some of the most overpriced NOS valves in the market.

the x10D is an example of a global negative feedback type amp.....cascaded common cathode sections tamed by negative feedback....

i find the simple buffer aka cathode follower more to my liking....

It was surprisingly effective at its designed purpose and brought a real sparkle and air to the presentation. This was predominantly down to its high input impedance vs low output impedance.
I only got rid of it when I started to get better results with Allan Wrights Super Linear Cathode Followers as a preamp.

My experience with the 6N1P is that they are universally bad. The have highly variable gain, high noise and high distortion. The 6H23 I have used, on the other hand, perform as well the best 6922 tubes.